Mean Opinion Score (MOS)

The explosion of smartphones (~1.5 billion sold in 2015), the proliferation of applications accessible through 4G mobile networks, and the advent of over-the-top (OTT) services have all put pressure on traditional service providers to differentiate themselves, keep the customer base loyal and, most importantly, recover revenues currently flowing to OTT providers and other MNO competitors.

In the world of communications systems testing and monitoring, MOS is an acronym for Mean Opinion Score. A MOS is used to evaluate and characterize the transmission characteristics of a telecommunications system.

No matter how solid a communications system is when it’s first implemented, things tend to go wrong over time. As you add new technology, change settings, have increased voice or data volumes, and more, it becomes a requirement that you monitor your communications systems to ensure they run as expected.

The phrase Active Monitoring can mean many different things, ranging from a periodic ping to verify that a server is reachable, to an HTTP transaction to measure responsiveness of a website, to a multi-party voice transaction to determine the quality levels that users are experiencing. Today, I am going to focus on active voice transactions.